Jesse cbitz king



J. C. KING.

ELECTRODE AND PROCESS OF MAKING SAME.

APPLICATION FILED MAY22.19I6.

Patented Aug. 5, 1919.

F/ca.

lm'enfar J. 6'. /I My F/GZ JESSE cmrz KING, or MONTREAL QUEBEC, omens.

mmcrnonn mn'inocnss or MAKING SAME.

Application filed May 22, 1916. Serial No. 99,104.

To all whom it may concern:

Be it known that I, Jnssn CRrrz KING, a citizen of the United States, and resident of the city of Montreal, in the Province of Quebec and Dominion of Canada, have invented certain new and useful Improvements in Electrodes and Processes of Making Same, of which the following is a full, clear, and exact description.

This invention relates to the manufacture of electrodes for use in electric furnaces and the like.

These electrodes are subject to considerable wasting away by burning under the action of air or other oxidizing gases between the carbon holders of the furnace electrodes and the smelting hearth. If the electrode is not protected by some means, the portion exposed to the air wastes away very rapidly. Several methods have been proposed torevent this, namely, b of the electrode wit a fireproofing material reinforced or held in position by wire fabric or other reinforcement; by electroplating a metal coating upon the surface of the electrode; by covering the electrode with an enamel or some form of paste; by converting the surface of the electrode into carbid or into graphite; or by pressing granular material, which-would resist or retard oxidation, into the surface of the electrode. Allof these methods have, however, failed to-a large extent when the material has been subjected to the action of-the air and gases and to the stresses caused by expansion and contraction at the high temperatures ofthe electric furnace, this failure being largely due to poor bonding of the material to the smooth surface of the electrode. 4

Heretofore, electrodes have been pressed or squirted through a smooth die or formed in a mold having a smooth wall, which delivered a finished electrode having a substantially smooth surface, to which an protective substances adhered with great iflicult especially when subjected to very high temperatures.

The main object of my invention is to pro vide a simple and inexpensive method-of producing an electrode having a roughened surface 'to which a suitable coating will readily adhere. j

In the drawings which illustrate my invention-:

Figure 1 is an elevation showing the elec- 4 Specification of-Letters Patent.

covering the sur ace sprayed uponthe surface of Patented Aug. 5 1919.

. trode with the protective covering inposition on the core.

Fig. 2 is a plan view of same.

Fig. 3'is a view showing the electrode with the roughening means partly removed.

Figs. 4, 5, areviews showing alternative forms.

In carrying out my invention in its pre: ferred form, I employ a mold 9'lined with wire fabric 10 or other suitable material .65 adapted to form irregularities upon the-su'r face. of the electrode or core. The -mold is then filled with some form of carbon in a plastic condition, and an electrode .of the desired shape, size and length is produced. This electrode, when set or hardened, is removed and the wire fabric .or like material is stripped from its surface, leaving same roughened by numerous irregular grooves 1 1-1, which are adapted to form keys to hold the coating material with which itis afterward covered. This irregular groovedsur face is then covered with a layer of paste 12, formed preferably of a mixture of fire clay and graphite, orother suitableinon-oxidiz so ing material, to the desired thickness. The electrode is then baked or dried to remove any water or gases, and the plastic coating is firmly bonded on to the electrode.

It wlllbe obvious that many modifications of the abovemethod maybe employed to produce the core of an electrode having a roughened or grooved surface, to which a non-oxidizing coating may be applied. In Fig. 4, I have shown a mold having its inner surface provided withridges 13, which may be formed spirally or otherwise, and which are adapted to produce an electrode having a grooved surface to which the nonoxidizing coating'may be applied. This mold will consist of a plurality of parts suitably held together, while the core is being formed, and adapted to be separated and removed without breaking or deforming the core itself." The mixture of fire clay and graphite may then be pressed, plastered or the electrode into the grooves to form a coating or layer, whichwhen baked with the electrode becomes virtually an integral part thereof, and will stand'very high temperatures and other stresses. g v In Fig. 5, I have shown a mold provided with recesses or grooves 14:,which will form projections or ridges on the surface of the 110 roughened surface of the electrode core in any suitable manner, by pressing, spraying or plastering, or it may be molded on to the surface, using the electrode as a core within a suitable mold.

Although I prefer to bake the non-oxidiz 1 ing coating with the core in an oven in a tective covering single operation, the carboncore may be formed with its roughened surface and baked, and the protective covering may be afterward applied and baked or dried on to the surface in a separate operation, the essential feature of the invention being the production of an electrode having a roughened, grooved or ridged surface with a proapplied thereto in such a manner as to produce an electrode having the core and surface covering integral and firmly bonded to resist high temperatures and other stresses to which it may be subjected.

Having thus described my invention, what I claim is 1. An electric furnace electrodehaving a roughened surface, and a protective coating overlying and baked on to face of the electrode whereby such surface is left in roughened condition, and then the surface of the electrode, substantially as described.

covering the surface of the electrode with a non-oxidizing protective material.

4. A method of making electrodes, which consists in bringing the material of the electrode while in plastic condition into and out of contact with a roughening. element of woven wire whereby the surface of the material is roughened, and then coating such roughened surface with a non-oxidizing protective coating. 4

5. A method of making electrodes, which consists in bringing the material of the electrode while in plastic condition into and out of contact with a roughening element of woven wire whereby the surface of the material is roughened, then coating such roughened surface with a non-oxidizing protective coating, and then baking the electrode and coating whereby the two are lnseparably bonded together.

6. The process of making electrodes which consists in roughening the surface of an unbaked electrode, applying a protective coating' thereon overlying said roughened sur face and of substantial thickness, and baking the electrode and the coating to drive off the volatile constituents. Y

7. The process of making carbon electrodes for electric furnaces which consists in roughening the surface of an unbaked elec trode, applying thereon to overlie said roughened surface a plastic protective coating, and baking the electrode and the coating to drive off the volatile constituents.

8. The process of making carbon electrodes for electric furnaces which consists in molding an electrode having a roughened surface, tective coating, and simultaneously bakin the electrode and the coating to drive 0 the volatile constituents contained in the electrode and the coating, and inseparably bond the two together. i

In witness whereof, I have hereunto set my hand, in the presence of two witnesses.

JESSE GRITZ KING.

Witnesses: C. W. TAYLOR,

G. M. MORELAND.

applying thereon a plastic pro- 

